Lively, a veteran actor who lives in Heber City, Utah, with wife Elain, also 66, previously had only half of a functioning heart and had trouble walking up a flight of stairs.

After Lively connected with Dr. Amit Patel, a professor at the University of Utah School of Medicine's Division of Cardiothoracic Surgery earlier this year, he became the first known patient to undergo retrograde gene therapy for the heart – injecting a patient's own stem cells in the heart to repair damaged muscle and arteries.

"I woke up the other morning and told my wife, 'I haven't felt this good in years,'" said Lively, who has four other children, in comments released by the University of Utah Health Care.

"I moved to Utah because of the snow, but I haven't been able to ski," Lively added. "I literally didn't have the heart to do it. Now, I'm excited about living the rest of my life instead of sitting around. Dr. Patel saved my life."